The goal of our research is to understand how visual processing is influenced by behavioral demands. The visual thalamus (dorsal lateral geniculate nucleus, LGN) plays a key role in this process, as it provides an intermediate relay between the retina and cortex, where transmission can be dynamically regulated based on multiple modulatory inputs. Although thalamic function has been studied extensively in vitro and under anesthesia, we still do not understand how behavioral state modulates the multiple pathways in LGN during awake visual processing. To address this gap we will study the mouse visual system, in order to take advantage of the range of molecular genetic tools that are available to identify and manipulate the underlying neural circuits. In our first aim, we will delineate the visal pathways present in mouse LGN, both in terms of neural coding and spatial organization, as measured with high-density in vivo electrophysiology. Next, we will determine how information in these pathways is modulated by behavioral state, by measuring the changes in visually-evoked neural activity associated with locomotion in alert subjects. Finally, we will test the role of neuromodulatory inputs in mediating the effects of behavioral state, using optogenetic manipulation of cholinergic circuitry. This work will advance our understanding of the selective gating of information in the brain, which is essential for both visual function and cognitive processes.